Fatal error: Uncaught Error: Class 'GuzzleHttp\Promise\RejectionException' not found in C:\inetpub\wwwroot\mantis\vendor\guzzlehttp\promises\src\AggregateException.php:7 Stack trace: #0 {main} thrown in C:\inetpub\wwwroot\mantis\vendor\guzzlehttp\promises\src\AggregateException.php on line 7